1. Field of the Invention
This invention relates to vibration isolation systems for superconducting magnets used in magnetic resonant imaging devices such that the vibration system is constructed of flexible isolators attached between the magnet and the cryocooler and, also, between the cryocooler and the cryostat. Such structures of this type, generally, allow substantially all of the forces created by the vibrating cryocooler to be dampened out while still providing adequate thermal conductivity and support in the vibration isolation system which, ultimately, increases the image resolution and the magnetic field uniformity of the imaging device.
2. Description of the Related Art
It is known, in superconducting magnet systems used in magnetic resonance imaging devices that in order to provide adequate thermal conductivity between the cryocooler and the magnet, one has to rigidly connect the second stage of the cryocooler directly to the magnet so that the magnet will be adequately maintained at a temperature of approximately 10 K. Also, the first stage of the cryocooler is rigidly attached by a direct connection to the thermal shield of the magnet so that shield will be maintained at a temperature of approximately 40 K. Finally, the entire cryocooler is rigidly attached by a direct connection to the cryostat vacuum enclosure in order to support the cryocooler assembly within the cryostat as the cryocooler contacts the magnet and the shield. While such rigid connections provide adequate thermal conductivity, any vibration produced by the cryocooler during its operation is transferred directly to the shield and the magnet which adversely affects the image resolution and magnet field uniformity of the imaging device, thereby, causing undesirable artifacts in the images produced. Consequently, a more advantageous system, then, would be presented if such amounts of vibration were reduced or eliminated while still providing adequate thermal conductivity and support.
It is apparent from the above that there exists a need in the art for a vibration isolation system which is lightweight through simplicity of parts and uniqueness of structure, and which at least equals the safety and thermal conductivity characteristics of known superconducting magnet mounts for magnetic resonance imaging devices, but which at the same time substantially reduces the amount of vibration being transferred from the cryocooler to the magnet, the shield and the cryostat. It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.